1. Field of the Invention
This invention relates to a P-i-n diode, and more particularly to the fabrication and structure of the intrinsic region (i-region) of the P-i-n diode.
2. Description of the Prior Art
The conventional P-i-n diode includes an n+ type cathode layer, an i-type layer, a p-type anode region, an anode electrode connected to the anode region, and a cathode electrode connected to the cathode region. The i-type layer is normally formed by growing an epitaxial layer of low impurity concentration on the cathode region. The p-type anode region is formed by diffusing p type impurity into the i-type layer. Accordingly, the P-i-n diode has a profile of impurity concentration as shown in FIG. 1.
Some of the problems experienced with this type of prior art P-i-n diode include a high forward-voltage drop, on the order of 1 volt, the reverse-recovery time is quite long, for instance 200-300 nanoseconds, and the power loss of the device is high necessitating a radiator.